Deputy Attorney General Paul McNulty said Monday he will resign, the highest-ranking Bush administration casualty in the furor over the firing of U.S. attorneys, The Associated Press has learned.

McNulty, who has served 18 months as the Justice Department’s second-in-command, announced his plans at a closed-door meeting of U.S. attorneys in San Antonio, according to two senior department aides. He said he will remain at the department until this fall or until the Senate approves a successor, the aides said.

[T]here has been tension between Gonzales loyalists and backers of Paul J. McNulty, the deputy attorney general.

Friends of D. Kyle Sampson, Mr. Gonzales’s former top aide, and Mr. Sampson’s former deputy, Monica Goodling, blame Mr. McNulty’s February testimony for accelerating the furor over the ousters by prompting prosecutors to speak openly about their dismissals. But Mr. McNulty’s allies have faulted Mr. Sampson for misleading Mr. McNulty and other officials about the origin of the dismissals and the extent of White House involvement.

Mr. McNulty is said by associates to be considering whether to step down soon.

UPDATE II: Gonzales releases a statement: “Paul is an outstanding public servant and a fine attorney who has been valued here at the Department, by me and so many others, as both a colleague and a friend. He will be missed. On behalf of the Department, I wish him well in his future endeavors.”

UPDATE III: The pro-McNulty spin on his leaving: “Justice aides said he has been considering leaving for months and never intended to serve more than two years as deputy attorney general. But his ultimate decision to step down, the aides said, was hastened by anger at being linked to the prosecutors’ purge that Congress is investigating to determine if eight U.S. attorneys were fired for political reasons.”

With Attorney General Alberto Gonzales on the ropes over the firings of eight U.S. attorneys, his deputy, Paul J. McNulty, is quietly testing the waters for a new job. […]

Even before the controversy erupted, Mr. McNulty, 49 years old, had been making plans to join the private sector after 24 years in government, which included a term as U.S. attorney in Virginia’s Eastern District, people familiar with his plans said. Knowing he would like to take a higher-paying job, partly to cover tuition for his four college-age children, well before the end of the administration, his friends recently have sent out feelers on his behalf for possible corporate and law-firm jobs, the people said.

UPDATE V: Sen. Schumer (D-NY) responds: “It seems ironic that Paul McNulty who at least tried to level with the committee goes while Gonzales who stonewalled the committee is still in charge. This administration owes us a lot better.”